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Title: Method and apparatus for reducing sample dispersion in turns and junctions of microchannel systems

Abstract

The performance of microchannel devices is improved by providing turns, wyes, tees, and other junctions that produce little dispersions of a sample as it traverses the turn or junction. The reduced dispersion results from contraction and expansion regions that reduce the cross-sectional area over some portion of the turn or junction. By carefully designing the geometries of these regions, sample dispersion in turns and junctions is reduced to levels comparable to the effects of ordinary diffusion. A numerical algorithm was employed to evolve low-dispersion geometries by computing the electric or pressure field within candidate configurations, sample transport through the turn or junction, and the overall effective dispersion. These devices should greatly increase flexibility in the design of microchannel devices by permitting the use of turns and junctions that do not induce large sample dispersion. In particular, the ability to fold electrophoretic and electrochrornatographic separation columns will allow dramatic improvements in the miniaturization of these devices. The low-lispersion devices are particularly suited to electrochromatographic and electrophoretic separations, as well as pressure-driven chromatographic separation. They are further applicable to microfluidic systems employing either electroosrnotic or pressure-driven flows for sample transport, reaction, mixing, dilution or synthesis.

Inventors:
 [1];  [2]
  1. Danville, CA
  2. Cardiff-by-the-Sea, CA
Issue Date:
Research Org.:
Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
OSTI Identifier:
873908
Patent Number(s):
6270641
Assignee:
Sandia Corporation (Albuquerque, NM)
Patent Classifications (CPCs):
Y - NEW / CROSS SECTIONAL TECHNOLOGIES Y10 - TECHNICAL SUBJECTS COVERED BY FORMER USPC Y10S - TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B - PERFORMING OPERATIONS B01 - PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL B01J - CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY
DOE Contract Number:  
AC04-94AL85000
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
method; apparatus; reducing; sample; dispersion; junctions; microchannel; systems; performance; devices; improved; providing; wyes; tees; produce; dispersions; traverses; junction; reduced; results; contraction; expansion; regions; reduce; cross-sectional; portion; carefully; designing; geometries; levels; comparable; effects; ordinary; diffusion; numerical; algorithm; employed; evolve; low-dispersion; computing; electric; pressure; field; candidate; configurations; transport; overall; effective; greatly; increase; flexibility; design; permitting; induce; particular; ability; fold; electrophoretic; electrochrornatographic; separation; columns; allow; dramatic; improvements; miniaturization; low-lispersion; particularly; suited; electrochromatographic; separations; pressure-driven; chromatographic; applicable; microfluidic; employing; electroosrnotic; flows; reaction; mixing; dilution; synthesis; sample transport; separation column; particularly suited; chromatographic separation; separation columns; systems employing; electrophoretic separations; channel systems; microfluidic systems; systems employ; greatly increase; electrophoretic separation; separation colum; channel device; /204/422/

Citation Formats

Griffiths, Stewart K, and Nilson, Robert H. Method and apparatus for reducing sample dispersion in turns and junctions of microchannel systems. United States: N. p., 2001. Web.
Griffiths, Stewart K, & Nilson, Robert H. Method and apparatus for reducing sample dispersion in turns and junctions of microchannel systems. United States.
Griffiths, Stewart K, and Nilson, Robert H. Mon . "Method and apparatus for reducing sample dispersion in turns and junctions of microchannel systems". United States. https://www.osti.gov/servlets/purl/873908.
@article{osti_873908,
title = {Method and apparatus for reducing sample dispersion in turns and junctions of microchannel systems},
author = {Griffiths, Stewart K and Nilson, Robert H},
abstractNote = {The performance of microchannel devices is improved by providing turns, wyes, tees, and other junctions that produce little dispersions of a sample as it traverses the turn or junction. The reduced dispersion results from contraction and expansion regions that reduce the cross-sectional area over some portion of the turn or junction. By carefully designing the geometries of these regions, sample dispersion in turns and junctions is reduced to levels comparable to the effects of ordinary diffusion. A numerical algorithm was employed to evolve low-dispersion geometries by computing the electric or pressure field within candidate configurations, sample transport through the turn or junction, and the overall effective dispersion. These devices should greatly increase flexibility in the design of microchannel devices by permitting the use of turns and junctions that do not induce large sample dispersion. In particular, the ability to fold electrophoretic and electrochrornatographic separation columns will allow dramatic improvements in the miniaturization of these devices. The low-lispersion devices are particularly suited to electrochromatographic and electrophoretic separations, as well as pressure-driven chromatographic separation. They are further applicable to microfluidic systems employing either electroosrnotic or pressure-driven flows for sample transport, reaction, mixing, dilution or synthesis.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2001},
month = {1}
}

Works referenced in this record:

Coiled columns and resolution in gas chromatography
journal, January 1960


Dispersion Sources for Compact Geometries on Microchips
journal, September 1998


Free boundary problem of ECM by alternating-field technique on inverted plane
journal, November 1975


Effects of Injection Schemes and Column Geometry on the Performance of Microchip Electrophoresis Devices
journal, April 1994


Contribution of capillary coiling to zone dispersion in capillary zone electrophoresis
journal, January 1995


Wormhole growth in soluble porous materials
journal, September 1990